Polyketone polymers are generally known in the art. Of particular interest among polyketone polymers is the class of linear alternating polymers of carbon monoxide and at least one ethylenically unsaturated hydrocarbon. This particular class of polyketone polymers is disclosed and claimed in numerous patents assigned to Shell Oil Company.
The addition of glass fiber and/or mineral fillers to reinforce polyketones is known in the art. Glass fibers, mica, and talc are examples of reinforcing materials or fillers that have been and are still being used.
It is known that these polyketone polymers have stability problems. These stability problems include ultraviolet (UV), melt stability, and heat aging stability. It has been suggested that the melt stability problem is caused by the tendency of the polymer to crosslink, especially at melt processing temperatures. It is known that glass fibers and mineral fillers in spite of their desirability tend to accelerate the crosslinking of the polymer, thereby excarbeting the problem of melt stability.
In spite of the successes that have been achieved towards melt stabilizing polyketones, the ideal melt stabilizing agent is yet to be discovered. Therefore, there continues to be a need and/or search for materials that can effectively melt stabilize polyketones.
It is a discovery of this invention that the addition of an effective amount of tribasic calcium phosphate (calcium apatite) to a glass fiber reinforced and/or mineral filled polyketone blend, provides a melt stabilizing effect to the polymer during melt processing.